A taco is deifnitely a sandwich, so is a gyro. That is absolutely undeniable! Instead of talking to idiot culinary experts and chefs, they should have asked any real Mexican ma. They should have supoenaed a barkeep in a MX neighborhood, where the cerveza is served with salt and lemon. The tortilla, or pita is the bread and it's stuffed with whatever. WHatever means anything they have, or feel like tossing on the tortilla. The word taco properly translates as sandwich. A burrito is simply a variant of a taco, where the tortilla is rolled instead os folded and the filling is mainly bean based.
I hate to burst your bunuelos, but a Mexican sandwich is called a torta.